Display panel or portion thereof with a graphical user interface



FIG. 1 is a front view of a display panel or portion thereof with a graphical user interface showing a first embodiment of the new design; and,

FIG. 2 is a front view of a second embodiment thereof.

The subject matter of the present disclosure includes graphical user interface components present. The broken lines depicting a display panel or portion thereof are included for the purpose of illustrating environmental structure and form no part of the design. The broken lines depicting portions of a graphical user interface are included for illustrating environmental aspects of a display panel or portion thereof with a graphical user interface and form no part of the design. 

CLAIM The ornamental design for display panel or portion thereof with a graphical user interface, as shown and described. 